The future of William Nylander with the Toronto Maple Leafs is still uncertain, with few updates available. However, a recent hint from Elliotte Friedman on his 32 Thoughts podcast gives us some insight into Nylander's plans for his NHL career and his role with the Leafs.
Friedman believes that Nylander truly wants to stay with the Maple Leafs for his entire career. It seems he's committed to Toronto, but there's a significant gap in the contract negotiations regarding how much he should be paid. As of now, it doesn't look like they're close to reaching an agreement.
Based on this information, it's clear that Nylander and the Leafs haven't figured out the details of a contract extension yet. Nevertheless, Nylander's preference is to stick with Toronto for the foreseeable future, if not for his entire NHL career.